Energy Management in Hybrid Electric Vehicles Based on Frequency Approach Compared to Dynamic Component Method -Lithium-Battery and Ultracapacitors

This paper presents a comparative study between the frequency approach and dynamic component method for energy management in Hybrid Electric Vehicles (HEVs). An auxiliary energy system based on ultracapacitors (U), and the High Energy Storage system focused on lithium-battery are used to share the requested energy by a vehicle. Ultracapacitors are linked to DC-bus through a bidirectional converter, and the lithium-battery is directly linked to DC-bus without a converter. An inverter and Electrical Machine (EM) are used to emulate the energetic demand of the Hybrid Electric Vehicle (HEV). The contribution of this paper is focused on a HEV power sharing between the ultracapacitors and the battery according to the dynamic responses of the sources. The performances of the proposed methods are evaluated through some simulations and experimental tests using United States drive cycle.